The estimation of the mutation rates of Y chromosome microsatellite loci, human Y chromosome phylogeny and human population divergence dates are the goals of this project. Approximately 500 individuals, drawn primarily from 5 Asian and 11 Native American population samples, are being genotyped at 9 microsatellite loci and 5 non-repetitive loci with known ancestral state, all located on the non-recombining, non-pseudoautosomal region of the human Y chromosome. Haplotypes will be constructed from the collected genotypes and population genetic parameters including heterozygosity and allelic repeat unit variance statistics will be calculated to compare population diversities and haplotype/population associations. Phylogenetic analysis using distance (population variance) and parsimony (interhaplotypic distance) methods will construct networks of evolutionarily-related populations and haplotypes. Linkage disequilibrium statistics will be calculated to estimate microsatellite mutation rates using population modeling approaches adapted from autosomal linkage disequilibrium mapping methods. These analyses will contribute to a understanding of the dispersal and migration of ancestral Asian populations into Asia and the Americas and will describe the relationships among descendent populations through the combined population genetic, phylogenetic and linkage disequilibrium analyses performed.